Settings now sync across devices through your Mozilla account. The
site whitelist and custom hidden element selectors are stored in
storage.sync; blocked request counters remain local to each machine.

The element picker is easier to exit: the status bar is more visible,
the Escape key closes it, and clicking the picker button again turns
it off.

No data is collected or transmitted. All settings are stored locally
via storage.local. webRequestBlocking is used solely to block requests
to known ad and tracker domains from a bundled list. No remote code
is loaded or executed.